Yippee............It now works thanks to
Mdorantes. I owe you a big wet sloppy kiss!!! - It took a bit of trial and error as well but I eventually got the Tyros to power on again.

In case any other Tyros owners get the same problem, this is what you do:

Hold down a C# chord in the second octave (C# F G#) to enter test mode.

Use the Tempo + key to page through all he tests until you get to the penultimate page. This is easy as you just go right to the end (Exit Test) and then back up one page using the Tempo minus key.

The page is called Factory Set and to activate it you press the accompianment start button. The reset to Factory Setup is instantaneous and you can then page forward and exit the test mode.

You dont have to perform any of the tests if you dont want to but there are some 80 of these and would be useful to make a note of them if you have a specific problem with the Tyros in future.

Of course I have lost all my user settings but most of these have now been restored as I had backed them up to my PC.

What I hadn't are the changed and saved vocal harmony user set, My Favourites in the Muic Finder and some sytem user setups for EQ, Noisegate and compression etc.

The Yamaha sites were a waste of time and effort - I found the site which lists all the hard factory reset instructions for all Yamaha musical instruments - Guess which ones were missing. Yes, both Tyros and PSR3000.

My local engineer got back to me and he had been on to Yamaha UK to see why or how my problem had occured. Apparantly, this is exactly what happens if you power off the pc without first de-activating the Tyros in the system tray on the PC!!!!

So - the moral is BE VERY CAREFUL WHEN USING USB BULK MODE.

Regards - Keith